System, Method and Apparatus for Lean Combustion with Plasma from an Electrical Arc

ABSTRACT

The present invention provides a plasma arc torch that can be used for lean combustion. The plasma arc torch includes a cylindrical vessel, an electrode housing connected to the first end of the cylindrical vessel such that a first electrode is (a) aligned with a longitudinal axis of the cylindrical vessel, and (b) extends into the cylindrical vessel, a linear actuator connected to the first electrode to adjust a position of the first electrode, a hollow electrode nozzle connected to the second end of the cylindrical vessel such that the center line of the hollow electrode nozzle is aligned with the longitudinal axis of the cylindrical vessel, and wherein the tangential inlet and the tangential outlet create a vortex within the cylindrical vessel, and the first electrode and the hollow electrode nozzle create a plasma that discharges through the hollow electrode nozzle.

PRIORITY CLAIM

This patent application is a continuation patent application of U.S.patent application Ser. No. 12/370,591 filed on Feb. 12, 2009 andentitled “System, Method and Apparatus for Lean Combustion with Plasmafrom an Electrical Arc,” which is a non-provisional patent applicationof U.S. provisional patent application Ser. No. 61/027,879 filed on Feb.12, 2008 and entitled, “System, Method and Apparatus for Lean Combustionwith Plasma from an Electrical Arc,” both of which are herebyincorporated by reference in their entirety.

FIELD OF THE INVENTION

The present invention relates generally to gas turbine engines. Morespecifically, the present invention relates to a supersonic leancombustion plasma steam reforming turbine engine that will combust lowBTU gas such as landfill gas, biogas, blast furnace gas, coke oven gasand syngas.

BACKGROUND OF THE INVENTION

There are many problems associated with lean fuel combustion or low BTUgas combustion in gas turbine engines. With the successful flight of theX-43A, hypersonic flight has achieved several technological goals andentered a new era. With further developments, it will reach TechnologyReadiness Level. However, FAA and EPA emission regulations in additionto the cost of fossil-based aviation fuels have pushed the aviationcommunity into research and development for highly efficient aircraftengines that work on alternative and/or renewable fuels. In particular,the land based gas turbine community has been conducting research forintegrating coal gasification with a combined cycle turbine (“IGCC”). Inany case, the combustion of the product from gasification of carboncontaining matter—synthesis gas (“syngas”)—requires major modificationsto current gas turbine engines. Because syngas has a low heating value(“LHV”) compared to natural gas, significantly more fuel must beinjected in an IGCC turbine than a natural gas turbine. Therefore, themass-flow—and thus the output power—of the gas turbine is much higherfor an IGCC application. For the same reason, the gas turbine's outputpower is flat-rated to very high temperatures.

Supersonic Combustion and Flame Holding

Problem 1: Gas Turbine to Ramjet or Scramjet Operations

High Bypass Fan Gas Turbines are the primary engines for transportationaircraft. Typical speeds are 893 km/h (482 kt) at altitude on aircraftsuch as the Boeing 777-300. Military aircraft use augmentors(“afterburners”) to achieve and sustain supersonic flight. Only the newF-22 raptor can sustain supersonic flight without the use of anaugmentor. Air breathing ramjets or scramjets are required to achievehypersonic flight using air. However, only one successful Scramjet hasbeen flown since the beginning of aviation. The major problem withramjets and scramjets can be traced back to the early problem of flameholding or preventing engine flame out. In addition, no matter whichconfiguration is chosen for Hypersonic Flight a problemremains—transition from subsonic to supersonic and finally hypersonicflight will require several different engines.

Problem 2: Lean Combustion or Low BTU Fuel Combustion

Fuel-lean combustion can increase efficiency while lowering emissions.However, current combustors cannot hold a flame during lean combustionconditions. Likewise, low BTU fuel such as syngas is difficult tocombust in current gas turbine engines.

Ansaldo Energia (Genoa, Italy) has engineered a new gas turbine V94.2K2that targets the low-Btu (3.5 MJ/Kg-7 MJ/Kg LHV) market. The K2 gasturbine builds on the design philosophy of Ansaldo Energia's V94.2K thatcan handle fuels with 8 MJ/Kg-13 MJ/Kg LHV. The K2 is intended forChinese and Eastern European markets where the company sees a demand forpower generation from industrial gases, such as Blast Furnace Gas (BFG)and Coke Oven Gas (COG).

The Lower Explosive Limit (LEL) and Upper Explosive Limit (UEL) forcommon hydrocarbon based fuels, such as diesel (0.6% to 7.5%), gasoline(1.4% to 7.6%), and natural gas (Methane—5.0% to 15%) is fairly limitedin range. On the other hand, syngas a product of natural gas (methane)steam reforming or gasification of hydrocarbons, coal, biomass, etc. iscomposed of hydrogen and carbon monoxide. The LEL and UEL for hydrogen(4% to 75%) and carbon monoxide (12.5% to 74.0%) are much broader thanthe parent fuel such as methane. Thus, this allows syngas (hydrogen+carbon monoxide) to be burned in a lean mode. The problem with syngasis that it is not widely available. It must be generated onsite by steamreforming natural gas or gasification of carbonaceous matter such ashydrocarbons or biomass. Typical gasifiers are very large and extremelyexpensive. However, a small and inexpensive plasma gasifier, such as theArcWhirl®, U.S. Pat. No. 7,422,695 issued on Sep. 9, 2008 to the presentinventor coupled to an IC engine could achieve both lean burn andsupersonic combustion by gasifying the fuel first then combusting it ina cyclone combustor that is driven by a turbocharger.

Problem 3: Match lit in Hurricane

Supersonic combustion has been compared to keeping a match lit in ahurricane or tornado. All gas turbines slow the flow of compressed airto below supersonic velocities in order to maintain a flame. This is dueto the inherit design of the flame-holding capabilities of the combustorfor a given turbine.

Move Match to Eye of Hurricane

It is well known that speeds within a cyclone can easily attainsupersonic velocities. For example, turbochargers and centrifugalcompressors easily attain speeds of over 100,000 RPM. Likewise, the aircirculating within a turbocharger would far exceed supersonic speeds.Thus, the present invention achieves supersonic combustion by utilizingthe centripetal forces within a rotating air column, such as a cycloneor hurricane for energy transfer, while utilizing the void, commonlyreferred to as the eye or vortex, in order to keep the match lit inorder to maintain ignition. Simply put, the match is moved from thewhirling column of air known as the shear wall to the eye or center ofthe hurricane.

Problem 4: Flame is Stretched Due to Whirl Flow & Melts Turbine

Placing the igniter within the center of the combustor is common formany types of gas turbine engines. Allison's C-18 to C-20 series of gasturbine engines utilize a front mounted axial flow compressor thatsweeps the compressed air to the combustor via externally mounted airconduits. If the combustor were redesigned such that the air tubesentered tangentially to the combustor housing, thus creating centrifugalflow within the redesigned cyclone or vortex combustor, then the igniterand fuel nozzle would be placed within the central void space or eye ofa whirling mass of air. However, this would create a detrimental effecton the compressor turbine if operated at supersonic combustion utilizingan intense igniter such as a plasma torch. The intense heat within thecentrally stretched out plasma flame would melt the center of thecompressor turbine.

Problem 5: Flame Out

It is well known that lean combustion can achieve high efficiency whileproducing low emissions. However, attempting to achieve lean combustionwithin current internal combustion (“IC”) engine designs may lead to lowreaction rates, flame extinction (“Flame Out”), instabilities, and mildheat release. Likewise, many IC engines are very sensitivity to fuel/airmixing.

With the current push for sequestering carbon or utilizing renewablefuels, a need exists for a relatively inexpensive turbine engine designthat can operate in a lean fuel combustion mode in addition to asupersonic combustion mode. If such a turbine could be easily coupled toa motor generator, high bypass fan or propeller, this would allow forrapid transition to renewable fuels for electrical generation, aviation,marine propulsion and thermal oxidation. The ability to transition fromsubsonic to supersonic then to hypersonic flight with the same enginewould solve many problems with reaching space at an affordable payloadrate. The ability to use the same air breathing supersonic combustionturbine as a steam plasma thruster in space solves the issues ofcarrying a large oxidizer payload.

SUMMARY OF THE INVENTION

The present invention provides a supersonic lean fuel combustion plasmaarc turbine that includes a plasma arc torch, a cyclone combustor and aturbocharger. The plasma arc torch includes a cylindrical vessel havinga first end and a second end, a tangential inlet connected to orproximate to the first end, a tangential outlet connected to orproximate to the second end, an electrode housing connected to the firstend of the cylindrical vessel such that a first electrode is (a) alignedwith a longitudinal axis of the cylindrical vessel, and (b) extends intothe cylindrical vessel, a hollow electrode nozzle connected to thesecond end of the cylindrical vessel such that the center line of thehollow electrode nozzle is aligned with the longitudinal axis of thecylindrical vessel, and wherein the tangential inlet and the tangentialoutlet create a vortex within the cylindrical vessel, and the firstelectrode and the hollow electrode nozzle create a plasma thatdischarges through the hollow electrode nozzle. The cyclone combustor isconnected to a hollow electrode nozzle of the plasma arc torch. Thecyclone combustor has a tangential entry, a tangential exit, and anexhaust outlet. The turbocharger has a turbine connected to a compressorvia a shaft. The turbine entry is connected to the tangential exit ofthe cyclone combustor, and a compressor exit is connected to thetangential entry of the cyclone combustor.

In addition, the present invention provides a plasma turbine thermaloxidizer that includes a plasma arc torch, a vessel housing at least oneceramic cyclone combustor, a first turbocharger and a secondturbocharger. The plasma arc torch includes a cylindrical vessel havinga first end and a second end, a tangential inlet connected to orproximate to the first end, a tangential outlet connected to orproximate to the second end, an electrode housing connected to the firstend of the cylindrical vessel such that a first electrode is (a) alignedwith a longitudinal axis of the cylindrical vessel, and (b) extends intothe cylindrical vessel, a hollow electrode nozzle connected to thesecond end of the cylindrical vessel such that the center line of thehollow electrode nozzle is aligned with the longitudinal axis of thecylindrical vessel, and wherein the tangential inlet and the tangentialoutlet create a vortex within the cylindrical vessel, and the firstelectrode and the hollow electrode nozzle create a plasma thatdischarges through the hollow electrode nozzle. The vessel has an airintake, a discharge exhaust and houses at least one ceramic cyclonecombustor connected to the hollow electrode nozzle. A first turbochargerhas a first turbine entry, a first turbine exit, a first compressorentry and a first compressor exit, wherein the first turbine entry isconnected to the discharge exhaust of the vessel and the compressor exitis attached to the tangential input of the plasma arc torch. A secondturbocharger has a second turbine entry, a second turbine exit, a secondcompressor entry and a second compressor exit, wherein the secondturbine entry is connected to the discharge exhaust of the vessel andthe second compressor exit connected to an air intake of the vesselhousing the ceramic cyclone combustor(s).

The present invention also provides a plasma turbine air breathing andsteam rocket that includes a plasma arc torch, a vessel housing at leastone ceramic cyclone combustor, a recuperator encapsulating an exhaustnozzle connected to a discharge exhaust to the vessel housing theceramic cyclone combustor(s), a first turbocompressor for compressingair, oxidant, or steam connected to the recuperator, a secondturbocompressor for pressuring fuel connected to the tangential input ofthe plasma arc torch, a valve system and a secondary oxidant injectionsystem. The plasma arc torch includes a cylindrical vessel having afirst end and a second end, a tangential inlet connected to or proximateto the first end, a tangential outlet connected to or proximate to thesecond end, an electrode housing connected to the first end of thecylindrical vessel such that a first electrode is (a) aligned with alongitudinal axis of the cylindrical vessel, and (b) extends into thecylindrical vessel, a hollow electrode nozzle connected to the secondend of the cylindrical vessel such that the center line of the hollowelectrode nozzle is aligned with the longitudinal axis of thecylindrical vessel, and wherein the tangential inlet and the tangentialoutlet create a vortex within the cylindrical vessel, and the firstelectrode and the hollow electrode nozzle create a plasma thatdischarges through the hollow electrode nozzle. The vessel houses atleast one ceramic cyclone combustor is connected to the hollow electrodenozzle. The valve system connects the tangential output of the plasmaarc torch to the recuperator that converts the first turbocompressorinto a vapor compressor pulling a suction on the recuperator while awater pump injects water into the recuperator and the compressed steamcools the ceramic cyclone combustor and enters into the cyclone andshifts the syngas to hydrogen and carbon dioxide while injecting asecondary oxidant into the nozzle, thus allowing the rocket totransition from air breathing to steam propulsion. The ceramic cyclonecombustor is cooled with a preheated combustion air from the firstturbocompressor which cooled the exhaust nozzle in the recuperator, anexhaust is scavenged to drive the first and second turbocompressors anda valve system means.

Moreover, the present invention provides a method for supersonic leanfuel combustion by creating an electric arc, generating a whirl flow toconfine a plasma from the electric arc, generating a combustion airwhirl flow, extracting a rotational energy from one or more hot gases,recuperating energy from the hot gases, and utilizing the electrical arcfor converting fuel to syngas while confining the plasma to the vortexof the whirling combustion air in order to maintain and hold a flame forsupersonic combustion while coupled to a means for extracting rotationalenergy from the hot lean combustion exhaust gas while recuperatingenergy for preheating the fuel and combustion air.

The present invention is described in detail below with reference to theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and further advantages of the invention may be betterunderstood by referring to the following description in conjunction withthe accompanying drawings, in which:

FIG. 1 is a diagram of a plasma arc torch in accordance with oneembodiment of the present invention;

FIG. 2 is a diagram of a Supersonic Lean Combustion Plasma Turbine inaccordance with one embodiment of the present invention;

FIG. 3 is a diagram of a Supersonic Lean Combustion Plasma Turbine MotorGenerator in accordance with another embodiment of the presentinvention;

FIG. 4 is a diagram of a Supersonic Lean Combustion Plasma Turbine HighBypass Fan in accordance with another embodiment of the presentinvention;

FIG. 5 is a diagram of a Supersonic Lean Combustion Plasma TurbinePropeller in accordance with another embodiment of the presentinvention;

FIG. 6 is a diagram of a Plasma Turbine Thermal Oxidizer in accordancewith another embodiment of the present invention; and

FIG. 7 is a diagram of a Plasma Turbine Air Breathing & Steam Rocketwith Recuperator in accordance with another embodiment of the presentinvention.

DETAILED DESCRIPTION OF THE INVENTION

While the making and using of various embodiments of the presentinvention are discussed in detail below, it should be appreciated thatthe present invention provides many applicable inventive concepts thatcan be embodied in a wide variety of specific contexts. The specificembodiments discussed herein are merely illustrative of specific ways tomake and use the invention and do not delimit the scope of theinvention.

Now referring to FIG. 1, a plasma arc torch 100 in accordance with oneembodiment of the present invention is shown. The plasma arc torch 100is a modified version of the ARCWHIRL® device disclosed in U.S. Pat. No.7,422,695 (which is hereby incorporated by reference in its entirety)that produces unexpected results. More specifically, by attaching adischarge volute 102 to the bottom of the vessel 104, closing off thevortex finder, replacing the bottom electrode with a hollow electrodenozzle 106, an electrical arc can be maintained while discharging plasma108 through the hollow electrode nozzle 106 regardless of how much gas(e.g., air), fluid (e.g., water) or steam 110 is injected into plasmaarc torch 100. In addition, when a valve (not shown) is connected to thedischarge volute 102, the mass flow of plasma 108 discharged from thehollow electrode nozzle 106 can be controlled by throttling the valve(not shown) while adjusting the position of the first electrode 112using the linear actuator 114.

As a result, plasma arc torch 100 includes a cylindrical vessel 104having a first end 116 and a second end 118. A tangential inlet 120 isconnected to or proximate to the first end 116 and a tangential outlet102 (discharge volute) is connected to or proximate to the second end118. An electrode housing 122 is connected to the first end 116 of thecylindrical vessel 104 such that a first electrode 112 is aligned withthe longitudinal axis 124 of the cylindrical vessel 104, extends intothe cylindrical vessel 104, and can be moved along the longitudinal axis124. Moreover, a linear actuator 114 is connected to the first electrode112 to adjust the position of the first electrode 112 within thecylindrical vessel 104 along the longitudinal axis of the cylindricalvessel 124 as indicated by arrows 126. The hollow electrode nozzle 106is connected to the second end 118 of the cylindrical vessel 104 suchthat the center line of the hollow electrode nozzle 106 is aligned withthe longitudinal axis 124 of the cylindrical vessel 104. The shape ofthe hollow portion 128 of the hollow electrode nozzle 106 can becylindrical or conical. Moreover, the hollow electrode nozzle 106 canextend to the second end 118 of the cylindrical vessel 104 or extendinto the cylindrical vessel 104 as shown. As shown in FIG. 1, thetangential inlet 120 is volute attached to the first end 116 of thecylindrical vessel 104, the tangential outlet 102 is a volute attachedto the second end 118 of the cylindrical vessel 104, the electrodehousing 122 is connected to the inlet volute 120, and the hollowelectrode nozzle 106 (cylindrical configuration) is connected to thedischarge volute 102. Note that the plasma arc torch 100 is not shown toscale.

A power supply 130 is electrically connected to the plasma arc torch 100such that the first electrode 112 serves as the cathode and the hollowelectrode nozzle 106 serves as the anode. The voltage, power and type ofthe power supply 130 is dependant upon the size, configuration andfunction of the plasma arc torch 100. A gas (e.g., air), fluid (e.g.,water) or steam 110 is introduced into the tangential inlet 120 to forma vortex 132 within the cylindrical vessel 104 and exit through thetangential outlet 102 as discharge 134. The vortex 132 confines theplasma 108 within in the vessel 104 by the inertia (inertial confinementas opposed to magnetic confinement) caused by the angular momentum ofthe vortex, whirling, cyclonic or swirling flow of the gas (e.g., air),fluid (e.g., water) or steam 110 around the interior of the cylindricalvessel 104. During startup, the linear actuator 114 moves the firstelectrode 112 into contact with the hollow electrode nozzle 106 and thendraws the first electrode 112 back to create an electrical arc whichforms the plasma 108 that is discharged through the hollow electrodenozzle 106. During operation, the linear actuator 114 can adjust theposition of the first electrode 112 to change the plasma 108 dischargeor account for extended use of the first electrode 112.

Referring now to FIG. 2, a diagram of a Supersonic Lean CombustionPlasma Turbine 200 in accordance with one embodiment of the presentinvention is shown. In order to gasify, crack, reform or pyrolyize fuel,the fuel 202 may be introduced into the system at one or more points:(a) introducing the fuel 202 a into the plasma 108 directly throughfirst electrode 112 wherein the first electrode 112 is hollow; (b)mixing (e.g., via an eductor) the fuel 202 b with the gas (e.g., air),fluid (e.g., water) or steam 110 introduced into the tangential inlet120 of the plasma arc torch 100; and (c) introducing (e.g., via aneductor) the fuel 202 c into the plasma 108 plume exiting the hollowelectrode nozzle 106. The plasma arch torch 100 is connected to acyclone combustor 204 with a tangential entry 206 and tangential exit208. The cyclone combustor 204 is connected to a turbocharger 210 viavalve 212. Hot gases enter into a turbine 214 of the turbocharger 210.The turbine 214 rotates a compressor 216 by means of a shaft with apinion 218. A compressor inlet valve 220 is connected to the compressor216. Compressor inlet valve 220 eliminates the need for stators toimpart a whirl flow to match the compressor wheel rotation direction. Inaddition, by utilizing a tapered reducer for the housing the velocity ofthe air 222 must increase in order to conserve angular momentum. Byutilizing a plunger style stopper valve assembly 224 coupled to a linearactuator 226, the mass flow can be pinched or reduced while maintainingvelocity. The physical separation of the compressor/turbine orturbocharger 210 from the combustor 204 allows for a radically differentdesign for gas turbines, power plants and airframes. The turbocharger210 can be located and oriented to maximize airflow while minimizingforeign object damage (FOD). In addition, the turbocharger 210 may becoupled to rotating unions and tubing in order to rotate or direct theexhaust from the turbine 214 for thrust vectoring. In order to maximizeefficiency a first stage recuperator 228 is placed on the dischargeexhaust from the turbine 214 and a second stage recuperator 230 is placeon the discharge exhaust from the combustor 204 via a valve 232.Compressed air 234 enters into the first stage recuperator 228 and theninto the second stage recuperator 230. The hot compressed air 236 thenenters into the combustor 204 via a volute with tangential entry 206.

More specifically, the compressor inlet valve 220 includes a volute witha tangential entry, a cone-shaped reducer connected to the volute, alinear actuator connected to the volute, and a cone-shaped stopperdisposed within the cone-shaped reducer and operably connected to thelinear actuator. A controller is connected to the linear actuator toadjust a gap between the cone-shaped stopper and the cone-shaped reducerto increase or decrease mass flow while maintaining whirl velocity toclosely match compressor tip velocity.

Although there are several variations and modes of operations a fewbrief examples will be given in order to quickly demonstrate theuniqueness as well as functionality of the Supersonic Lean CombustionPlasma Turbine 200. A vortex is formed within the plasma arc torch 100using water, steam, fuel or any other fluid 110. The arc is struck and aplasma is discharged into the eye of the cyclone combustor 204. Theplasma syngas plume entering into the cyclone combustor 204 is also theigniter. Since it is in the eye of the cyclone it will be extended alongthe longitudinal axis of the combustor 204 and into valve 232. Bythrottling valves 212 and 232 the turbine can be operated from a takeoffmode and transition to supersonic and hypersonic flight. The purpose ofthe pinion 218 on the turbocharger 210 in combination with separatingthe combustor 204 from the compressor 216 and turbine 214 allows for aunique and completely unobvious mode of operation.

Referring now to FIG. 3, a diagram of a Supersonic Lean CombustionPlasma Turbine Motor Generator 300 in accordance with another embodimentof the present invention is shown. Two or more Plasma Turbines 200 (200a and 200 b as shown) are coupled to a bull gear 302 in a locked-trainfashion. The bull gear 302 drives a motor generator 306 via drive shaft304. This configuration allows for operating in a very fuel efficientand cost effective means. The first Plasma Turbine 200 a is started byusing the motor to rotate the pinions in order to rotate the compressor.The cyclone valve's stopper is opened to allow air into the compressor.The second Plasma Turbine's 200 b stopper is placed in a closed positionin order to unload the compressor. This can also be accomplished byplacing electrical clutches on the pinion. When air flow enters into thecombustor, the plasma arc torch 100 is ignited with only water or steamflowing through it in the same rotational direction as the cyclonecombustor. Once the plasma arc is stabilized fuel is flowed into theplasma arc torch 100 and gasified and synthesized into hydrogen andcarbon monoxide. The hot syngas plasma flows into the cyclone combustor.It is ignited and lean combusted and flowed out of the combustor via thetangential exit. Valve is fully opened while valve is shut in order tomaximize flow into the turbine. Valves and are then adjusted accordingto torque loading on the pinion in addition to turbine and compressorspeed.

By operating only one combustor at its maximum efficiency the generatorcan be operated as a spinning reserve. All utility companies within theUS are required to maintain “Spinning Reserves.” In order to come up tofull power additional Plasma Turbines can be started almost instantlywith very little lag time. This annular Plasma Turbine configuration mayhave multiple bull gears on a single shaft with each bull gearconsisting of multiple Plasma Turbines.

Now referring to FIG. 4, a diagram of a Supersonic Lean CombustionPlasma Turbine High Bypass Fan 400 in accordance with another embodimentof the present invention is shown. Two or more Plasma Turbines 200 (200a and 200 b as shown) are coupled to a bull gear 302 in a locked-trainfashion. A high bypass fan 402 is attached to the shaft 304. Likewise, asmall motor generator may be attached to the opposite end of the shaftfor starting and inflight electrical needs. Once again the PlasmaTurbine configuration allows for maximizing fuel efficiency while idlingat the gate and taxing by operating only one Plasma Turbine attached tothe bull gear. Prior to takeoff all Plasma Turbines are brought onlineto maximize thrust. After takeoff Plasma Turbines may be taken offlineto maximize fuel efficiency during climbout and at cruise altitude andspeed.

When the pilot is ready to transition to supersonic flight the turbineinlet valve is slowly closed while the combustor valve is opened. Thehigh bypass fan may be feathered in order to reduce speed of the bullgear or to reduce drag. Likewise an inlet cowling may be used to closeair flow to the high bypass fan. Air flow into the combustor is directlydue to speed of the aircraft. This is accomplished with an additionalthree way valve (not shown) connected to the combustor tangential entry.Thus, the combination of the plasma arc torch 100 and the cyclonecombustor coupled to a unique exhaust valve allows for a true plasmaturbine scramjet that can be operated in a supersonic lean fuelcombustion mode.

Referring to FIG. 5, a diagram of a Supersonic Lean Combustion PlasmaTurbine Propeller in accordance with another embodiment of the presentinvention is shown, which is similar to the motor generator and highbypass fan, the system allows for a very unique marine turbine. Incomparison, the US Navy's Spruance class destroyers were one of thefirst class of Naval ships to utilize high powered marinized aircraftturbines. Two GE LM-2500 Gas Turbine Engines were coupled to the portshaft via a bull gear and two GE LM-2500 Gas Turbine Engines werecoupled to the starboard shaft via a bull gear. This gave the ship atotal of 100,000 shaft horsepower. In order to operate in the most fuelefficient mode, only one engine was operated while the other engine wasdecoupled from the bull gear via a friction and spur gear type clutch.The other shaft was placed in a trail mode position and allowed to spinor rotate freely. If full power was needed the other 3 gas turbineengines required about 3 minutes to start in an emergency mode.

There were two major problems associated with the LM-2500 coupled to abull gear. First, when starting from a dead in the water position, theengineers had to conduct a dead shaft pickup. This required engaging theclutch and placing the friction brake on which held the power turbine.The turbine was started and hot gases flowed across a non-moving powerturbine section. The brake was released and the power turbine rotatedthus turning the bull gear. The variable pitched propeller was usuallyplaced at zero pitch.

Returning back to FIG. 5, the bull gear 302 with multiple PlasmaTurbines 200 (200 a and 200 b are shown) may be attached to a driveshaft 304 that is connected to a propeller 502. However, this system canbe greatly augmented with a motor generator (not shown) directlyattached to the drive shaft 304. In fact, the propeller 502 can beeliminated and replaced with an all electric drive pod. Thus, FIG. 3would be installed and simply would provide electrical power to theelectric drive pod. Neither rotating a shaft for transportation andpropulsion purposes nor rotating a large motor generator may be requiredfrom the Plasma Turbine System.

Now referring to FIG. 6, a diagram of Plasma Turbine Thermal Oxidizer600 in accordance with another embodiment of the present invention isshown. The plasma arc torch 100 is attached to a commonly availablefilter vessel 602 which houses a ceramic hydrocylone 604. Ceramichydrocyclones 604 are available from CoorsTek and Natco.

More specifically, the vessel 602 has an air intake 606, a dischargeexhaust 608 and houses at least one ceramic cyclone combustor 604connected to the hollow electrode nozzle of the plasma arc torch 100. Afirst turbocharger 610 has a first turbine entry 612, a first turbineexit 614, a first compressor entry 616 and a first compressor exit 618.A second turbocharger 602 has a second turbine entry 622, a secondturbine exit 624, a second compressor entry 626 and a second compressorexit 628. The first turbine entry 612 and the second turbine entry 622are connected to the discharge exhaust 608 of the vessel 602. A firstrecuperator 630 is connected to the first turbine exit 614, the firstcompressor exit 618 and the tangential input of the plasma arc torch 100such that a compressed fuel from the first compressor exit 618 is heatedby a first exhaust 632 from the first turbine exit 614 and enters thetangential input of the plasma arc torch 100. A second recuperator 634connected to the second turbine exit 624, the second compressor exit 628and the air intake 606 of the vessel 602 such that a compressed air fromthe second compressor exit 628 is heated by a second exhaust 636 fromthe second turbine exit 624 and enters the air intake 606 of the vessel602.

Many landfills as well as wastewater treatment plants produce a low BTUfuel referred to as biogas. Likewise, many industries produce a very lowBTU offgas that must be thermally oxidized or incinerated. The plasmaturbine thermal oxidizer achieves lean combustion by first gasifying thelow BTU fuel in another low BTU fuel—syngas. However, since the syngashas a larger ignition range (LEL to UEL) it can be combusted at highflow rates without additional fuel.

The system is operated in the following mode. The plasma arc torch 100is turned on to establish an arc. Water or steam may be flowed in theplasma arc torch 100 to form the whirl or vortex flow. Air is flowedinto a compressor through a recuperator and into the vessel. The airsurrounds and cools the ceramic cyclone combustor. The air enters intothe ceramic hydrocyclone tangentially then exits as a hot gas into theturbines. Once air flow is established the low BTU gas is flowed into acompressor then into a recuperator. The hot low BTU gas is flowed intothe plasma arc torch 100 where it is steam reformed into syngas. Onceagain, the syngas plasma enters into apex valve of the ceramic cyclonecombustor. The syngas is lean combusted and traverses to the turbine,recuperator and then exhausted for additional uses. In this system, theturbochargers may be installed with high speed alternators for providingelectricity to operate the power supplies for the plasma arc torch 100.

This system is especially useful at wastewater treatment plants(“WWTPs”). Biogas is often produced from digesters. Likewise, all WWTPsuse air to aerate wastewater. Since the Plasma Turbine Thermal Oxidizeroperates in a lean fuel combustion mode, there is ample oxygen leftwithin the exhaust gas. This gas can be used for aerating wastewater.Likewise, plasma arc torch 100 can be used to disinfect water whilesteam reforming biogas. In addition, biosolids can be gasified with theplasma arc torch 100 to eliminate disposal problems and costs.

Referring now to FIG. 7, a diagram of a Plasma Turbine Air Breathing &Steam Rocket with Recuperator 700 in accordance with another embodimentof the present invention is shown. The thermal oxidizer 600 of FIG. 6can easily be converted into a rocket or process heater. A nozzle 702and recuperator 704 are attached to the outlet 608 of the combustor 604.Air or an oxidant are flowed into the recuperator 704. The hot air oroxidant exits the recuperator 704 and enters into the vessel 602 andinto the ceramic cyclone combustor 604. Fuel is pressurized via aturbocompressor 706 and enters into the plasma arc torch 100 where it isconverted or cracked into syngas. The syngas plasma plume ejecting intothe ceramic cyclone combustor 604 is controlled via a multi-positionfuel recirculation valve 708. A portion of the fuel may flow into thenozzle 702 to increase thrust. In order to drive the turbines a portionof the hot exhaust gas is scavenged and flowed to the inlets of the fuelturbocompressor 706 and turbocharger 710. When used as an air breathingrocket, upon reaching altitudes where lean combustion cannot besustained due a lack of oxygen molecules, in lieu of carrying anoxidant, the rocket would carry water. The water in pumped into therecuperator 704 to generate steam. The turbocharger 710 is valved suchthat it can pull a vacuum on the recuperator 704. The turbocharger 710is then operated as a vapor compressor. The compressed steam is flowedin the vessel 602. The extremely hot syngas reacts with the steam in theceramic cyclone combustor 604 for conversion to hydrogen and carbondioxide via the water gas shift reaction. Since the water gas shiftreaction is exothermic this will ensure that the steam remains in thevapor state. A small amount of liquid oxidizer may be added to combustthe hydrogen.

Finally, the present invention provides a method for supersonic leanfuel combustion by creating an electric arc, generating a whirl flow toconfine a plasma from the electric arc, generating a combustion airwhirl flow, extracting a rotational energy from one or more hot gases,recuperating energy from the hot gases, and utilizing the electrical arcfor converting fuel to syngas while confining the plasma to the vortexof the whirling combustion air in order to maintain and hold a flame forsupersonic combustion while coupled to a means for extracting rotationalenergy from the hot lean combustion exhaust gas while recuperatingenergy for preheating the fuel and combustion air.

The foregoing description of the apparatus and methods of the inventionin preferred and alternative embodiments and variations, and theforegoing examples of processes for which the invention may bebeneficially used, are intended to be illustrative and not for purposeof limitation. The invention is susceptible to still further variationsand alternative embodiments within the full scope of the invention,recited in the following claims.

What is claimed is:
 1. A supersonic lean fuel combustion plasma arcturbine comprising: a plasma arc torch comprising: a cylindrical vesselhaving a first end and a second end, a tangential inlet connected to orproximate to the first end, a tangential outlet connected to orproximate to the second end, an electrode housing connected to the firstend of the cylindrical vessel such that a first electrode is (a) alignedwith a longitudinal axis of the cylindrical vessel, and (b) extends intothe cylindrical vessel, a hollow electrode nozzle connected to thesecond end of the cylindrical vessel such that the center line of thehollow electrode nozzle is aligned with the longitudinal axis of thecylindrical vessel, and wherein the tangential inlet and the tangentialoutlet create a vortex within the cylindrical vessel, and the firstelectrode and the hollow electrode nozzle create a plasma thatdischarges through the hollow electrode nozzle; a cyclone combustorconnected to the hollow electrode nozzle of the plasma arc torch,wherein the cyclone combustor has a tangential entry, a tangential exit,and an exhaust outlet; and a turbocharger having a turbine connected toa compressor via a shaft, wherein an turbine entry is connected to thetangential exit of the cyclone combustor, a compressor exit is connectedto the tangential entry of the cyclone combustor.
 2. The supersonic leanfuel combustion plasma arc turbine as recited in claim 1, furthercomprising a first valve disposed between the tangential exit of thecyclone combustor and a the turbine entry.
 3. The supersonic lean fuelcombustion plasma arc turbine as recited in claim 1, further comprisingcompressor inlet valve connected to a compressor entry of thecompressor.
 4. The supersonic lean fuel combustion plasma arc turbine asrecited in claim 3, wherein the compressor inlet valve comprises: avolute with a tangential entry; a cone-shaped reducer connected to thevolute; a linear actuator connected to the volute, a cone-shaped stopperdisposed within the cone-shaped reducer and operably connected to thelinear actuator; and a controller for connected to the linear actuatorto adjust a gap between the cone-shaped stopper and the cone-shapedreducer to increase or decrease mass flow while maintaining whirlvelocity to closely match compressor tip velocity.
 5. The supersoniclean fuel combustion plasma arc turbine as recited in claim 1, furthercomprising: a first stage recuperator connected to a discharge exhaustof the turbine; a second stage recuperator connected to a dischargeexhaust of the cyclone combuster; and wherein the compressor exit isconnected to the first stage recuperator such that a compressed air fromthe compressor is heated by the first stage recuperator and the secondstage recuperator and enters the combustor via the tangential entry ofthe combustor.
 6. The supersonic lean fuel combustion plasma arc turbineas recited in claim 5, further comprising a second valve disposedbetween the discharge exhaust of the cyclone combustor and the secondstage recuperator.
 7. The supersonic lean fuel combustion plasma arcturbine as recited in claim 1, further comprising a pinon gear attachedto the shaft between the turbine and the compressor.
 8. The supersoniclean fuel combustion plasma arc turbine as recited in claim 7, furthercomprising a bull gear and a drive shaft connected to the pinion gear.9. The supersonic lean fuel combustion plasma arc turbine as recited inclaim 8, further comprising a motor generator connected to the driveshaft.
 10. The supersonic lean fuel combustion plasma arc turbine asrecited in claim 8, further comprising a high bypass fan connected tothe drive shaft.
 11. The supersonic lean fuel combustion plasma arcturbine as recited in claim 8, further comprising a propeller connectedto the drive shaft.
 12. The supersonic lean fuel combustion plasma arcturbine as recited in claim 1, wherein the first electrode is hollow anda fuel is introduced into the hollow first electrode.
 13. The supersoniclean fuel combustion plasma arc turbine as recited in claim 1, wherein afuel is introduced into the tangential inlet of the plasma arc torch.14. The supersonic lean fuel combustion plasma arc turbine as recited inclaim 1, wherein a fuel is introduced into the plasma that dischargesthrough the hollow electrode nozzle.
 15. The supersonic lean fuelcombustion plasma arc turbine as recited in claim 1, wherein a gas, afluid or steam is introduced into the tangential inlet of the plasma arctorch.
 16. A plasma turbine thermal oxidizer comprising: a plasma arctorch comprising: a cylindrical vessel having a first end and a secondend, a tangential inlet connected to or proximate to the first end, atangential outlet connected to or proximate to the second end, anelectrode housing connected to the first end of the cylindrical vesselsuch that a first electrode is (a) aligned with a longitudinal axis ofthe cylindrical vessel, and (b) extends into the cylindrical vessel, ahollow electrode nozzle connected to the second end of the cylindricalvessel such that the center line of the hollow electrode nozzle isaligned with the longitudinal axis of the cylindrical vessel, andwherein the tangential inlet and the tangential outlet create a vortexwithin the cylindrical vessel, and the first electrode and the hollowelectrode nozzle create a plasma that discharges through the hollowelectrode nozzle; a vessel having an air intake, a discharge exhaust andhousing at least one ceramic cyclone combustor connected to the hollowelectrode nozzle; a first turbocharger having a first turbine entry, afirst turbine exit, a first compressor entry and a first compressorexit, wherein the first turbine entry is connected to the dischargeexhaust of the vessel and the compressor exit is attached to thetangential input of the plasma arc torch; and a second turbochargerhaving a second turbine entry, a second turbine exit, a secondcompressor entry and a second compressor exit, wherein the secondturbine entry is connected to the discharge exhaust of the vessel andthe second compressor exit connected to an air intake of the vesselhousing the ceramic cyclone combustor(s).
 17. The plasma turbine thermaloxidizer as recited in claim 16, further comprising: a first recuperatorconnected to the first turbine exit, the first compressor exit and thetangential input of the plasma arc torch such that a compressed fuelfrom the first compressor exit is heated by a first exhaust from thefirst turbine exit and enters the tangential input of the plasma arctorch; and a second recuperator connected to the second turbine exit,the second compressor exit and the air intake of the vessel such that acompressed air from the second compressor exit is heated by a secondexhaust from the second turbine exit and enters the air intake of thevessel.
 18. A plasma turbine air breathing and steam rocket comprising:a plasma arc torch comprising: a cylindrical vessel having a first endand a second end, a tangential inlet connected to or proximate to thefirst end, a tangential outlet connected to or proximate to the secondend, an electrode housing connected to the first end of the cylindricalvessel such that a first electrode is (a) aligned with a longitudinalaxis of the cylindrical vessel, and (b) extends into the cylindricalvessel, a hollow electrode nozzle connected to the second end of thecylindrical vessel such that the center line of the hollow electrodenozzle is aligned with the longitudinal axis of the cylindrical vessel,and wherein the tangential inlet and the tangential outlet create avortex within the cylindrical vessel, and the first electrode and thehollow electrode nozzle create a plasma that discharges through thehollow electrode nozzle; a vessel housing at least one ceramic cyclonecombustor connected to the hollow electrode nozzle; a recuperatorencapsulating an exhaust nozzle connected to a discharge exhaust to thevessel housing the ceramic cyclone combustor(s); a first turbocompressorfor compressing air, oxidant, or steam connected to the recuperator; asecond turbocompressor for pressuring fuel connected to the tangentialinput of the plasma arc torch; a valve system connecting the tangentialoutput of the plasma arc torch to the recuperator that converts thefirst turbocompressor into a vapor compressor pulling a suction on therecuperator while a water pump injects water into the recuperator andthe compressed steam cools the ceramic cyclone combustor and enters intothe ceramic cyclone combustor and shifts the syngas to hydrogen andcarbon dioxide while injecting a secondary oxidant into the nozzle, thusallowing the rocket to transition from air breathing to steampropulsion; a secondary oxidant injection system; and wherein theceramic cyclone combustor is cooled with a preheated combustion air fromthe first turbocompressor which cooled the exhaust nozzle in therecuperator, an exhaust is scavenged to drive the first and secondturbocompressors and a valve system means.
 19. A method for supersoniclean fuel combustion comprising the steps of: providing the apparatus ofclaim 1; creating an electric arc; generating a whirl flow to confine aplasma from the electric arc; generating a combustion air whirl flow;extracting a rotational energy from one or more hot gases; recuperatingenergy from the hot gases; and utilizing the electrical arc forconverting fuel to syngas while confining the plasma to the vortex ofthe whirling combustion air in order to maintain and hold a flame forsupersonic combustion while coupled to a means for extracting rotationalenergy from the hot lean combustion exhaust gas while recuperatingenergy for preheating the fuel and combustion air.